Depth estimation for ordinary high water of streams in the Mobile District of the U.S. Army Corps of Engineers, Alabama and adjacent states

Abstract

The 25 percent streamflow duration and corresponding depth were selected to represent ordinary high water. Statistical relations of 25 percent flow duration depth to eight basin parameters were analyzed using a stepwise linear regression procedure. A procedure for estimating "ordinary high water" depth was derived using one independent variable drainage area size. Two equations were derived; the standard error of estimate of the equation for hydrologic area 1, the Appalachian Plateaus, is 26 percent and for area 2, the Coastal Plains province, is 39 percent. The equations apply where the stream channels or streamflow is not significantly altered by man's activities.

Hydrologic analysis of field delineated ordinary high water marks for rivers and streams

“…The use of multiple streamgages creates a streamflow record with an effective length that is suitable for flood frequency analysis. Regional flood frequency analysis will help provide context for the general behavior of streamflow in a particular region but introduce spatial and temporal uncertainty into the metrics (Harkins and Green 1981).…”